More Nuggets from the American Cancer Society Mine

The American Cancer Society Cohort was the two punch after the Harvard 6-cities study struck the first blow regarding mortality effects of air pollution at the community level. The ACS study covered many more cities, with less depth than the Harvard study. C.A. Pope, III, was the lead author on the ACS study. Pope had started the modern charge of community studies with publications about the decrease in respiratory conditions in the Utah Valley when the local steel mill [or smelter?] went on strike.

The oil and car companies screamed for reanalysis. The Health Effects Institute, a creature of the car companies and EPA, sponsored that reanalysis, with Dan Krewski, from Ottawa [the great white and clean north, other than for asbestos] as the PI and statistical guru. At the time, BrooklynDodger called Krewski's group the "unoriginal investigators" in contrast to the original investigators.

There was great potential for mayhem. Instead, it appears that Krewski got along with Pope and Dockery, because they all seem to publish together in various permutations.

The review article abstracted below relates the history. Bottom line conclusion: Robust associations between ambient fine particulate air pollution and elevated risks of cardiopulmonary and lung cancer mortality were clearly evident, providing the strongest evidence to date that long-term exposure to fine particles is an important health risk.

The pace of reanalysis and republication [not republicanism] will likely step up if EPA moves forward on a new particulate NAAQS.


>>>>>>>>>>>>>>>>
J Toxicol Environ Health A. 2005 Jul;68(13):1093-109.

Mortality and long-term exposure to ambient air pollution: ongoing analyses based on the american cancer society cohort.

Krewski D, Burnett R, Jerrett M, Pope CA, Rainham D, Calle E, Thurston G, Thun M.

McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Ontario, Canada.

This article provides an overview of previous analysis and reanalysis of the American Cancer Society (ACS) cohort, along with an indication of current ongoing analyses of the cohort with additional follow-up information through to 2000. Results of the first analysis conducted by Pope et al. (1995) showed that higher average sulfate levels were associated with increased mortality, particularly from cardiopulmonary disease. A reanalysis of the ACS cohort, undertaken by Krewski et al. (2000), found the original risk estimates for fine-particle and sulfate air pollution to be highly robust against alternative statistical techniques and spatial modeling approaches. A detailed investigation of covariate effects found a significant modifying effect of education with risk of mortality associated with fine particles declining with increasing educational attainment. Pope et al. (2002) subsequently reported results of a subsequent study using an additional 10 yr of follow-up of the ACS cohort. This updated analysis included gaseous copollutant and new fine-particle measurements, more comprehensive information on occupational exposures, dietary variables, and the most recent developments in statistical modeling integrating random effects and nonparametric spatial smoothing into the Cox proportional hazards model. Robust associations between ambient fine particulate air pollution and elevated risks of cardiopulmonary and lung cancer mortality were clearly evident, providing the strongest evidence to date that long-term exposure to fine particles is an important health risk. Current ongoing analysis using the extended follow-up information will explore the role of ecologic, economic, and, demographic covariates in the particulate air pollution and mortality association. This analysis will also provide insight into the role of spatial autocorrelation at multiple geographic scales, and whether critical instances in time of exposure to fine particles influence the risk of mortality from cardiopulmonary and lung cancer. Information on the influence of covariates at multiple scales and of critical exposure time windows can assist policymakers in establishing timelines for regulatory interventions that maximize population health benefits.